Investigation of Cancer Cell Identification in Suspension by Bioimpedance Spectroscopy a Dissertation Submitted to the University of Sussex in Partial Fulfillment of the Requirements for the Degree of Master of Philosophy

Bioimpedance has been of great significance for its applications in exploring the electrical properties of biological materials. It has been widely applied in cancer detection of tissues. However, studies at the tissue level have not achieved a consensus over the changes of impedance parameters due to the complex structure and heterogeneity of tissue. Moreover, the relationship of biological changes and their corresponding electrical changes is still unclear. Impedance research at the cellular level will help to establish the relationship between biological and electrical properties of cancer cells, which will ultimately promote the development of cancer detection. In this thesis an application of impedance spectroscopy for cancer cell identification in suspension was proposed and investigated. Two breast cell lines, MCF-10A and MCF-7 representing normal cells and cancer cells respectively were investigated in suspension by impedance spectroscopy. In order to choose a suitable method for cell suspension measurement, a comparison of two-electrode and four-electrode measurements was carried out before the investigation of cell suspensions. Electrode polarization, which is the major problem of two-electrode measurement, was studied in order to interpret the results of the two-electrode measurement. The results indicated both impedance and its parameters were significantly different between MCF-10A and MCF-7. To further analyse the electrical parameters in the two cell lines, an electrical circuit model and a physical model were adopted in this study. The impedance parameters involved were analysed and compared between two cell lines. Furthermore, the biological difference between the two cell lines was explored with biological assays. Based on the electrical and biological changes, the relationship between electrical parameters and biological features of normal cells and cancer cells was analysed and the possible biological factors influencing the electrical properties of cell will be discussed in this thesis.